I've literally just finished reading 'Hollowland' by Amanda Hocking, after reading it in less than 24 hrs. It's an enjoyable read, and it keeps you gripped at times.

It's about a 19 yr old girl, Remy, who has to travel across America to find her little brother, to make sure he's safe. A year or so before, a virus broke out which turned people to 'zombies', and if you got bitten, you turned into one too. Her little brother is sick, and he was evacuated, but he was only one evacuated form the quarantine they were in. She's told he was taken to another quarantine a while away, so she escapes to try and find it. While fighting zombies, and marauders along the way. Most of the human race had been wiped out/turned into zombies.

There's a sub plot romance, but it's not truly focused on until a little later into the book. I was glad about that, as sometimes I find they start too early on /: